We are always surprised by how many visitors to our website are looking for information about poison sumac, not poison ivy and oak.
It turns out that poison sumac is extremely hard to find in most areas: I met a trained botanist with decades in New England who had never seen it!
Poison sumac only grows in VERY wet areas, often with its roots right in the water, or on the very edge of the water.
But this kind of sumac grows along very many roads, almost as common as poison ivy, so people may think that they are seeing poison sumac.
This kind of sumac, and also smooth sumac, have dense fruiting bodies that stand upwards whereas poison sumac berries hang downwards in loose groups.